1. Field of the Invention
This invention relates to hose clips primarily preventing various piping hoses connected to connecting pipes in automotive vehicles, for example, and more particularly to such a hose clip adapted to be inherently capable of holding its spread-diameter state without use of a separate holder.
2. Description of the Prior Art
Various hoses are generally used in an engine compartment of an automotive vehicle for cooling the engine and supplying fuel to the engine. These hoses include those intended for use with a high pressurized fluid, which need to be prevented from falling off from connecting pipes. A generally ring-shaped metal hose clip is conventionally used so that the hose is reliably clamped by its inherent strong spring force. It is desirable that the hose clip be conveyed to a work place in the state that its diameter is previously spread in consideration of working efficiency there. This state of the hose clip will be referred to as "spread-diameter state."
The following methods are known for holding the hose clip in its spread-diameter state. First, the hose clip is generally formed by bending a spring band plate into the shape of a ring. Grip strips are formed on both ends of the band plate for spreading its diameter. The grip strips are caused to come close to each other in the spread-diameter state of the hose clip and then, the grip strips are strode by a generally U-shaped member or holder such that the hose clip is held in the spread-diameter state.
However, the holder needs to be pulled out before the hose is clamped by the above-described hose clip. The holders, after pulled out of the hose clips, are thrown away around the work place. The used holders are thus scattered about, which worsens the working environment. Furthermore, the hose clip cannot be again held in the spread-diameter state without the holder when it is required to be held in the spread-diameter state after the hose has been clamped by the hose clip.
In view of the foregoing, the prior art has recently proposed so-called "holderless" type hose clips which can be held in the spread-diameter without using the holder. For example, U.S. Pat. No. 4,773,129 to Rudolf Muhr discloses a hose clamp comprising a ring-shaped clamping body having one end rising radially outwardly and further, bent approximately perpendicularly, in which end a locking recess is formed. The other end of the clamping body is bent radially outwardly and a locking projection is formed in the end. The locking projection is inserted into the locking recess such that the clamping body is held in the spread-diameter state. In order that the hose clamp is released from the spread-diameter state, the locking projection is pushed down by the distal end of a tool such as a screwdriver so that the locking projection is disengaged from the locking recess.
In the above-described releasing operation, however, the distal end of the screwdriver is likely to slip and accordingly, the whole hose clamp becomes unstable. Accordingly, a stable releasing operation cannot be expected. In such an unstable releasing operation, an excessive force tends to be applied to the locking projection in the manipulation so that it is pushed down, which plastically deforms the clamping body radially. Consequently, circularity of the hose clamp is deviated, which results in drop and nonuniformity in clamping pressure of the clamping body. Japanese Published Utility Model Registration Application No. 64-29591 is directed to the same subject mater as in the above-described U.S. Pat. No. 4,773,129.
Japanese Published Utility Model Registration Application No. 3-86277 discloses another technique of the holderless type hose clip. The disclosed hose clip comprises a clip body having at one end a rising bridge portion and at the other end a rising manipulation end and a rising engagement claw. The engagement claw is engaged with the bridge portion such that the hose clip is held in the spread-diameter state. When the hose clip is turned from the free or clamping state to the spread-diameter state, the manipulation necessitates both gripping circumferentially of the hose clip and an axial displacement. The directions of both manipulations intersect to each other and accordingly, the manipulations are quite difficult. Furthermore, the disclosed hose clip is directed to one having a relatively small spring force and is subjected to manual operation. Accordingly, this hose clip can be used even when the directions of the manipulations intersect to each other. However, a special tool is required for the manipulation when the hose clip has a relatively large spring force. Such a special tool has a complicate construction and is difficult to be manufactured. Furthermore, the construction of the hose clip itself is also rendered complicate.